Protein kinases are known to mediate cell proliferation. Inhibition of such kinases is useful in the treatment of cell proliferative diseases.
Some substituted bicyclic nitrogen heterocycles are known in the art for their protein kinase, specifically tyrosine kinase, inhibitory activity. WO 01/29042 and WO 01/29041 relates to alkylamino-substituted dihydropyrimido[4,5-d]pyrimidinone derivatives with p38 inhibitory activity. WO 99/61444 relates to dihydropyrimido[4,5-d]pyrimidinones, substituted with aryl and hetarylamines, sulfides, sulfoxides and sulfones as inhibitors for cyclin-dependent kinases (cdks) and tyrosine kinases. Aryl and heteroarylamine substituted dihydropyrimido[4,5-d]pyrimidinones are also discussed in WO 00/24744 as inhibitors of T-cell tyrosine kinase p56lck.
There continues to be a need for easily synthesized, small-molecule compounds effective in inhibiting the catalytic activity of protein kinases.